第45页 - 亮点给力提优课时作业本七年级数学江苏版

D

A

$(-5+2)×(－7-1)=24$

50

95

41

$ \begin{aligned}解：原式&=－0.25+\frac{1}{4}-8+\frac{27}{8}×\frac{4}{9} \\ &=－\frac{13}{2} \\ \end{aligned}$

$ \begin{aligned}解：原式&=-8-3×18-9÷(-2) \\ &=－\frac{115}{2} \\ \end{aligned}$

$ \begin{aligned}解：原式&=\frac {1}{2}×\frac {3}{2}×\frac {2}{3}×\frac {4}{3}×\frac {3}{4}×… ×\frac {2023}{2024}×\frac {2024}{2024} \\ &=\frac {1}{2}×\frac {2025}{2024} \\ &=\frac {2025}{4048} \\ \end{aligned}$